Hydrochloric Acid → Ethyl 6-chloro-1H-pyrrolo[2,3-b]pyridine-2-carboxylate

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Reaction Steps

HCl gas is bubbled through a solution of 6-chloro-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid (36 g, 183 mmol) in ethanol (500 mL) at 0° C. for 30 min. The reaction mixture is then heated at reflux for 16 h. The solvent is evaporated and the residue is diluted with CH2Cl2 and filtered. The filtrate is evaporated and the residue is washed with diethyl ether (2×250 mL). The organic layers are dried (Na2SO4) and concentrated. The crude residue is purified by passing through the column of neutral alumina, eluting with 10% EtOAc/hexane to afford the title compound as a white solid (10 g, 25%).

Provenance & Evidence